Stamping is the process by which a metal blank (“blank”) is formed into a part. A die draw system is used to form or “stamp” a metal blank into a part that is used for forming, for example, a panel of a vehicle. The draw die process is the first forming operation in the stamping process and the most critical operation in forming the part. It is estimated that 70% of all failures in the stamping process occur in the draw die process. A failure can occur, for example, if the blank is stretched too thin or if not enough pressure is applied to the blank when the draw die process is performed.
To better control the draw die process, a layer of lubrication may be applied to the blank prior to the draw die process. The lubrication is applied to reduce the friction between the blank and the press of the die draw system. If too much lubrication is applied to the blank the amount of strain in the blank will increase, thereby resulting in failure. If too little lubrication is applied to the blank, the amount of strain in the blank will buckle or wrinkle thereby resulting in failure. Similarly, the amount of cushion that is applied at the binders effects the draw die process. If the amount of cushion tonnage at the binders is too great, the amount of strain in the blank increases past the ultimate tensile strength of the blank, thereby resulting in a thinning failure. If the amount of cushion tonnage at the binders is too great, the amount of strain in the blank decreases and does not reach the yield strength, thereby resulting in an insufficient thinning failure.